Editor’s Note
What follows is a brief review of a product that has been around for a long time: the Platypus GravityWorks filtration system.
We haven’t conducted a comprehensive long term review of this system to date, even though it’s a popular product with our reader base. Also, the Platypus GravityWorks filter is uniquely positioned as a viable option for group water treatment, and when considered in that context, it’s weight can be justified.
I’ve used the Platypus GravityWorks filtration system on some long treks with Scout groups. The context that made this decision justifiable included:
- Assignment of water collection and treatment duties to an individual who is responsible for supplying water to the entire crew (thus avoiding the need to have each person use it in turn);
- Travel in pristine mountain environments where water clarity is high (to avoid the risk of filter clogging as a result of dirty water from snowmelt / glacial melt).
This review provides an alternate perspective from someone who is newer to gravity filtration and is looking at using the Platypus GravityWorks filter for personal use.
– RJ
Introduction
This Platypus GravityWorks filter review will show how this water filtration system provides the backcountry hiker with a reliable and convenient means of filtering water while on the trail. Additionally, this system is available in two versions: The 4.0L (135 oz.) and the 2.0L (68 oz.) models which provide options for filtering water into a clean water reservoir bag or directly into bottles. Also, the gravity fed system offers a quick and effortless approach to filtering large amounts of water while leaving the user hands-free to work on other essential camp chores.
Features
- 8 liter (135 oz.) total water capacity (perfect for groups or water storage on those longs dry hauls)
- Dirty zip-lock style bag
-Easy to fill by dipping the bag into water or using a cup to fill it from smaller sources
-Hanging strap with buckle
-Quick disconnect tube attachment - In-line gravity water filter
-Fast hands-free operation
-Easily backflush the microfilter for maintenance in the field - Clean reservoir bag
-Hanging strap with buckle
-Screw on hose adaptor for secure seal
-Hose shut-off clamp for storing and dispensing water at leisure - Storage sack
- Options for using other Platypus products to create a system just right for you
Specifications
- Weight:
-Manufacturer states 11.5 oz. (326 g)
-My scale reads 11.7 oz (331 g) - Dimensions: 3.25”W x 9.5”L
- Filter Media: Hollow Fiber
- Filter pore size (microns): 0.2
- Flow Rate: 1.75 liters (59 oz.) per minute
- Cartridge Life: 1500 liters (50721 oz.)
- Effective against Protozoa, Bacteria, and Particulates
- Ineffective against Chemicals/Toxins, Viruses
Field Use
I grew up on hand-pump operated water filter systems and knew no different until a recent rekindling of my adventurous spirit took me back into the wilderness last year. Seeing a gravity filter for the first time? It was a no-brainer… hands-free operation while leaving you available to do other essential camp tasks (not to mention no more sitting on a cold river bank away from the fire for 15 minutes trying to pump into a reservoir bag). Also, having less moving parts to break in my opinion is a winner! In my search for the latest and lightest gear, I found the Platypus GravityWorks system. Available in 4.0L (135 oz.) and 2.0L (68 oz.) versions which allow several options to integrate with other water storage products.
My Rationale for Selection
I selected the 4.0L version for two reasons: 1) Sometimes I hike in groups of 4-5 people, and I felt that this system would provide an excellent resource for supplying a large group. 2) There are areas that I hike where reliable water can be 10+ miles (16+ km) apart. Additionally, if I want to carry extra water, then I can use the up to 8 liters (271 oz.) water capacity to haul it.
Usage Context
That said, I used the system on an 18.3 mile (29.5 km)/2 day hike earlier this year just as it was starting to warm up here in Alabama. I carried the complete kit: dirty bag, clean bag, and all the hoses. Also, I never touched the clean bag or the hose attached to it. I used the dirty bag to scoop water from a nearby stream, hung it on a tree (the hang strap with buckle is a handy addition), and filtered the water straight into my water bladder. In the future, unless I plan to provide water for a group around a campsite, I will only carry the dirty bag with the hose and in-line filter attached which weighs in at 7.3 ounces (207 g).
I’ve gone the way of all the other crazy “gram-counters” out there utilizing electronic scales and spreadsheets to formulate the lowest possible pack weight, even cutting the tags out of my already lightweight tent. Who needs tags anyway? I don’t care about all that useless manufacturer information. WEIGHT! Or the lack thereof and the function of a product is all I care about. Also, I like for stuff to look cool, but that’s not so essential.
Performance
The system worked great when I used it in the field. It did what it was supposed to do, and you can’t ask for more than that. It filtered water quickly and cleanly. The water tasted great, and the whole operation was smooth from start to finish. In my testing, I found the filtering time for 4 liters (135 oz.) of water to be between 4:13 and 4:23. Of course, I have done one thing to adapt mine by cutting a small portion (6” or so)(152 mm) of the tubing to place on the clean side of the filter with the hose shut-off clamp attached. This makes a small portion of the clean tube ready for placement inside your bladder or bottle for filling.
The system is clearly marked to prevent contamination of the clean bag and the connection for each bag is different. They have a quick disconnect for the dirty side and a screw on attachment for the clean side. Also, the filter is also clearly marked with directional arrows indicating a direction of flow. While the zip-lock style opening of the dirty bag allows for easy water filling and emptying, and it’s large enough to clean and dry for storage. The screw off style cap on the clean bag allows for quick emptying as well.
Photos were taken on the Alabama Pinhoti Trail/Section 4 (April 2016).
Performance Highlights
- Easy filling of the Dirty water bag using the wide zip-lock style opening.
- No Pumping – Quick gravity filtration straight into your water bladder, bottle, or Clean water reservoir bag.
- The bag material is sturdy and durable.
- Straps on both bags include buckles to make hanging around long tree branches straightforward and efficient.
- The in-line hose shut-off clamp can be used to control the amount of dirty water filtered into the Clean bag. It dispenses drinkable water from the Clean bag when you detach the hose from the filter.
- Backflush capability enables frequent maintenance to ensure filter performance. Guidelines suggest a 4-second backflush with every use.
Summary
Strengths
- Large capacity to accommodate groups or extra water storage along a dry trail.
- Treatment is effective against Protozoa, Bacteria, and Particulates.
- The absence of a pump gives the peace-of-mind that with fewer moving parts there is a lower chance of system failure.
- Lightweight design with the option to reduce weight by leaving the Clean bag behind.
- The system rolls up into a compact and easily packable bundle and comes with a storage bag.
- Options for integrating with other Platypus accessories to customize your system.
- Design allows for easy cleaning and drying for storage of both bags.
- Clear plastic allows for easy inspection.
- Cost is competitive with similar type filters systems.
Limitations
- Other reviews have stated that with extremely dirty water the filter can become clogged with particulates. This may require pre-filtering water through a cloth before using the system.
- The filter can freeze if not emptied and stored in a warm environment.
- With shallow water sources, it can be difficult to fill the Dirty bag directly from the source. A cup can be used to remedy this problem.
- The filter does not treat chemicals/toxins or viruses. A water “purifier” is needed if these are concerns.
Recommendations
I’ve only used the system once in the field, but it worked flawlessly, and I look forward to many more trips with my Platypus. It offers a user-friendly and speedy way to filter water while in the backcountry. I find it superior to pumping by cutting down the time and effort involved and eliminating the moving parts that are subject to break. If viruses are a concern UV or chemical treatment should also be considered. To me, the advantages of this system, as compared to similar systems on the market, are the overall capacity, weight, dirty water filling method, the clear reservoir bags, and the options Platypus offers for integrating accessories.
The 4.0L (135 oz.) version provides a way for me to collect large quantities of water from sources away from the campsite and carry it back for the night. If I fill my 2.5 liters (84.5 oz.) in-pack water bladder at the source then fill the dirty bag to take back to camp, I will have plenty of water in reserve to cook and clean. I will have enough water to refill all my containers before hitting the trail again. The smaller 2.0L (68 oz.) is also available with minimal weight savings and substitutes the clean water bag for a 2-liter soft bottle. Depending upon your specific needs either model should make a great addition to your kit.
Where to Buy the Platypus GravityWorks Filter
Where to Buy Platypus GravityWorks Water Filter System Kit - 2 Liter
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